


Personality Proof

by nitohkousuke



Category: Kamen Rider Build
Genre: Anxiety, Dissociation, Gen, Identity Issues, Math, Mental Health Issues, depersonalization kinda
Language: English
Status: Completed
Published: 2017-10-17
Updated: 2017-10-17
Packaged: 2019-01-18 16:45:56
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,273
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12392076
Author URL: https://archiveofourown.org/users/nitohkousuke/pseuds/nitohkousuke
Summary: Sento Kiryu is a logical person.Things if you go about them a logical way have to make sense?A look at Sento's Identity issues and approach to them.





	Personality Proof

**Author's Note:**

> This is totally vent fic don't mind me

Sometimes his dreams are him in the tank. It’s only the tank. The green liquid that consumes and consumes and he can’t breathe even though there’s a mask making sure it doesn’t drown him. But he is drowning. In fear. In static. In a body that’s his and isn’t his because while he can see. While he can see the bat man and the green and the scientist. While he can see through his eyes, they aren’t his. There are images and sounds and textures but no thoughts. There’s no thought or even feelings. The feelings are his now. Fear and anxiety. And while he’s sure that’s what any person would feel in the tank drowning, drowning, choking, dying…..he can’t connect those feelings. It’s static. It’s like his mind is wrapped in tape and bubble wrap and he’s on the outside tearing layer and layer and layer but there’s more layers. And he’s sure there’s a connection. There’s an understanding. But it’s not there. And the more he reaches……the less certain he is that it was ever him. Less certain there was a him or is a him. or that he’s….real.

Sometimes his dreams are static. They’re there. But they’re static. Like he’s trying to access something that isn’t his. But it should be. Nothing is picking up reception. Dreams are the brain trying to tell you something. They use your memories to construct ideas. People’s face. Concepts. Words. Situations. But when so much of your life is missing……it’s like trying to access a wiped hard drive.

Isn’t that what he is?

Sometimes his dreams are nothing. And he wakes up suddenly, startled and disorientated. His brain is blank and he tries to recall who he is, and in the grogginess, when his brain can’t connect 1 and 2 and 3. When there is nothing. When it is blank, his brain immediately reels. And he jumps up and tries to grab every single thing that’s his. He goes to the board and writes down all of his favorite formulas and proofs and equations. He starts at party tricks like solving the quadratic formula through completing the square and he moves to harder things like a simple quantum physics problem. And usually, it’s enough. He can sit back. He can look at the board, look at his books, look at his clothes, and his bed. Look at the belongings that he’s amassed in the year…and he can see who he is.

And usually, he can look at this collection of a person, because that’s what a person is right? Like a proof. You let the things equate to traits. To personality quirks and habits and hobbies. And if you Let the equations equal his intelligence. The books equal his tastes in literature. His clothes to his fashion sense. The cleanliness of his room to his tidiness. You can take all these facts and say that if all these items exist and imply a personality. If they imply traits. And if he exists and thus must have a personality. Then there for, if they are his, then this must be his personality and his traits. It’s a simple logical conclusion. And usually he can start and end and even put his filled-in square at the bottom of the proof as it’s logical and complete. And whatever panic attack he is on the verge of, ends suddenly and quickly as if it never happened. And it didn’t as far as anyone is concerned.

Except it doesn’t. It’s still there. It’s boiling inside his skin, and all he can do is convince himself he’s right and dissociate the feeling from him. But it in a box on the shelf, and put a pretty box of something nicer in front. Out of sight. Out of mind.

Because Sento is logical and infallible. He is smart and a hero. And he doesn’t have time for his own issues. Because…

Build is more important than his memory issues. Even if they consume him. Even if they threaten to destroy him. Even if it takes everything he is and topples it over. Because that’s the kind of person he wants to be. That’s the kind of person…he is…right?

And usually its so easy. It’s so easy to do this. It’s not actually but its just doable enough that Sento can do it and no one can notice that he’s actually a bunch of traits and copies of things taped together in a make shift fashion of things he doesn’t even know are his. Usually he can pass. And Misora never notices and Soichi doesn’t. And if they do, they don’t ask. And that’s just how it should be. Because he tries his best to pretend it doesn’t consume his every waking thought.

And even with Ryuuga, who either sleeps like a brick or Sento is quiet enough that he doesn’t notice, Sento is able to continue on with this farce as if he’s totally and utterly fine. Maybe Ryuuga notices but he can’t connect those dots. Sento would prefer that he never does. It’s not something he needs to know about.

And even on the night that Ryuuga yells at him, BUILD OR MEMORIES. Sento says quickly and easily that it’s Build. Because well obviously in that case, there was a way he could help people easily without a question. And his memories weren’t so easily tangible. And besides, whoever he is will come naturally right? Even without his memories he’s the same person. He’s the same person so it doesn’t matter.

It’s easier to chose a hypothetical when only one answer is viable. It’s easier to pretend the other isn’t even that important when you don’t have access.

That night he doesn’t sleep but silently writes on every single chalk board he has, every single formula and proof he knows and erases and continues and erases and continues. Because this is who he is. This is who he is. Physics. Physics. His personality is a bunch of equations strapped together and once his memories come back to him, he’ll know exactly who he is and he’ll be some shut in physicist and everything will be fine! Because if A then B because A implies B. So if Sento knows physics, then he must have been a physicist because that’s what that implies. A physicist who cares about people. Who works hard. Because that’s who he is. That’s who he wants to be.

And now, Sento sits on his bed shaking, in one hand is a picture of a face that’s his. It’s definitely his. All the information implies that its his. But he can’t connect the dots. He can’t connect the feelings. Because everything he knows. Everything he’s put together is now. Wrong right? He had a theory and it’d seemed so solid. Theories in science are fact after all. Because they’ve been tested and tested and tested. And now. Now he realized, it wasn’t a theory. It was a hypothesis. A hypothesis that he’d not tested correctly. He was using his bias to mess up the experiment. Only seeing what he wanted. And now, someone has thrown in front of him a different result. One that he could replicate. One that he could replicate that is factual and should make sense. But it doesn't. It doesn't make sense. There was still something missing. And Sento HATED not knowing. He was a genius. Everything is easy. Logic. Math. Physics. Everything is easy. The only issue is his memory and that of course will come to him. But it doesn't and instead someone has given him things that don't make sense.

And it’s not even just the photo or Tetsuya or the fact that the evidence suggests that he killed Katsuragi, it’s his own behaviour. It’s his screaming and anger. It’s the fact that the logical, calm, and rational personality he’d constructed because he thought it was his…is shattered and broken so easily. He had just yelled at Ryuuga for being selfish, and he’d nearly sacrificed an entire room of people for the sake of his memories. He’d hesitated when he had to choose….and it’d taken RYUUGA of all people to have him snap to his senses. Or…were they really his senses? Is this really him? Is he Sento Kiryu logical, heroic, and genius physicist or is he Satou Taro selfish, loud, and buffoonish rock and roll star?

Or is he neither? Who is he? If a person doesn’t have memories, are they even a person? You can make new memories, but people are so intensely their experiences. And you can’t just construct a person on a years worth of memories. That doesn’t make a personality. You need some sort of base.

…..Is Satou Taro really his base?

Crumbling up the photo in his hand and chucking it, Sento rises to his feet. Because. So what if that’s who he was. That’s not who he is? Right? He’s logical and science and smart and a hero. But as he reaches for the chalk he can feel that anger coursing through him. He can feel the selfishness and attitude he never thought could be his but sounds so much like Tarou. And he wonders….what is real and what is constructed? And does it matter?

What defines a person?

He’s Sento Kiryu now. That’s what he tells himself as he grabs a piece of chalk and immediately goes through his usual coping mechanisms. But this time….his brain is too far submerged in anxiety. He starts a proof. A mid level proof concerning convergence of a infinite series in the complex plane. It’s one of his favorites. But he realizes half way through. Is it his favorite? Would Sato Taro even know what a complex plane was? What is his favorite? Who is he? No. No. He’s working on math. He’s working on this. This proves that it doesn’t matter. But he can’t. Remember the next step. He can’t think. He can’t breathe. What if…..what his mere existence not only caused the death of that scientist but also the death of another person’s identity? What if it caused Ryuuga’s terrible fucking situation? Did Ryuuga’s girlfriend die because of his involvement? Are there others who he’s hurt? Was he selfish for existing when it had hurt so many people simply by being him? Who was he? Did he deserve to exist?

Sento tries to use his usual grounding method but it doesn’t work. He presses the chalk harder against the board, trying to use test after test to show convergence…..but nothing is working. He knows this answer. He should. And the chalk snaps in his hand as he realizes he’s crying. Softly, silently, no one needs to know. But he’s shaking and crying and he just wants to know. He wants to know who he is already. What he is. Is this who he is? Is Sento just a placeholder? What has he been doing all this time? He tries to wipe his face but only manages to smear chalk over the tears….like him trying to wipe smatterings of a personality of a smashed blank state. And sure they stick. You can see them. But you can see the face underneath easily. No one is fooled. Is that how everyone sees him? Who do they see? Who is he?

And he turns to the room and tries to look it over. Tries to go through the steps. But he didn’t pick any of those books. They’re Misora and Soichi’s. His clothes are the blandest and simplest things that he simply picked with Soichi’s help. There’s nothing defining about them. And his tidiness is also….just a learned trait from being here. When you have little, it’s easy to be clean. And this problem was…..another thing that might not even be his. And even if it was, he couldn’t do it.

But he had to. He was Sento Kiryu.

….Wasn’t he?

Looking over the half done proof, the chalk smeared across his face, he takes a breath. He centers himself. He’s done this so many time’s hasn’t he. Dissociated himself from everything he can’t handle. There is no problem. He’s not afraid. It doesn’t matter. He takes a towel and wipes the chalk from his face. Just like he wipes his feelings as if nothing is wrong.

Nothing is wrong.

And he manages to complete the proof like it’s nothing. Just like how he’ll be able to continue on tomorrow as if this never happened. He never cried. He never broke down. If no one observes it, it can’t be proven.

Sento Kiryu isn’t afraid. Isn’t upset. There’s nothing wrong.

….So he crawls back into bed and prays for a night of static. Briefly he considers taking sleeping pills. Or just not sleeping at all. Both of which will hinder too much to be viable options.

And as he passes out, looking over at Ryuuga sprawled out with the Cross-Z Dragon curled next to him….with Misora curled around her stuffed bunny…..

He tries to focus on the future. On saving everyone. On clearing Ryuuga’s name.

…Not on the fact that there’s nothing he’s more afraid of than not knowing about the truth. Whether its the truth about himself....the truth about what happened. The truth about everything.

Sometimes, you can’t solve a problem because there’s just not enough data. And you just…..have to wait…..and sometimes the answer you get….that you waited so long for….isn’t what you want to know.

But that’s just how life is.


End file.
